FR3059488A1 - ELECTRIC MACHINE FOR A MOTOR VEHICLE - Google Patents

Abstract

The invention relates to a support assembly for an electric machine (100) comprising a housing (118) having a housing (116) of longitudinal axis (132) inside which the stator (114) is to be mounted (114). of the electric machine (100) and a cover (122) for closing an opening in the housing (116) to be traversed by the rotor of the electric machine (100). According to the invention, the casing (1118) comprises a first annular piece (126, 174) for radially inwardly supporting the stator (114) of the electric machine (100) and a second piece (128, 186) supporting the first piece (126, 174), the first annular piece (126, 174) being connected to the second piece (128, 186) and the cover (122) by means of elastically deformable means.

Description

059 488

61479 ® FRENCH REPUBLIC

NATIONAL INSTITUTE OF INDUSTRIAL PROPERTY © Publication number:

(to be used only for reproduction orders)

©) National registration number

COURBEVOIE © Int Cl ⁸ : H 02 K 5/24 (2017.01)

PATENT INVENTION APPLICATION

A1

©) Date of filing: 25.11.16. © Applicant (s): VALEO CONTROL SYSTEMS (30) Priority: ENGINE Simplified joint-stock company - FR. @ Inventor (s): LEBRASSEUR PATRICK and MACHET FRANÇOIS. (43) Date of public availability of the request: 01.06.18 Bulletin 18/22. ©) List of documents cited in the report preliminary research: Refer to end of present booklet (© References to other national documents ® Holder (s): VALEO CONTROL SYSTEMS related: ENGINE Simplified joint-stock company. ©) Extension request (s): © Agent (s): VALEO CONTROL SYSTEMS ENGINE Simplified joint-stock company.

(04) ELECTRIC MACHINE FOR MOTOR VEHICLE.

FR 3 059 488 - A1 _ The invention relates to a support assembly for an electric machine (100) comprising a casing (118) comprising a housing (116) with a longitudinal axis (132) inside which is intended to be mounted the stator (114) of the electric machine (100) and a cover (122) for closing an opening in the housing (116) intended to be crossed by the rotor of the electric machine (100). According to the invention, the casing (1118) comprises a first annular part (126,174) intended to radially support internally the stator (114) of the electric machine (100) and a second part (128, 186) supporting the first part (126 , 174), the first annular part (126, 174) being connected to the second part (128, 186) and to the cover (122) by means of elastically deformable means.

100

164

148

118

128

ELECTRIC MACHINE FOR MOTOR VEHICLE

The present invention relates to a housing of an electric machine as well as an electric machine and a motor equipped with such a housing.

In the case where the torque setpoint of a heat engine varies suddenly and where the engine supercharging aimed at helping it to follow the torque setpoint, is only obtained thanks to a turbocharger, the response time of the latter, again called "turbolag" poses a problem. To remedy this problem, various solutions are known, for example the use of several selectively active turbochargers, an electric compressor or even a mechanical centrifugal compressor.

An electric supercharging compressor is conventionally used in the air intake line of a thermal combustion engine of a motor vehicle, upstream or downstream of a turbocharger.

FIG. 1 represents an electric motor 10 intended to supply power to the compressor. The electric motor 10 comprises a guided rotor 12 rotating in an annular stator 14 of the electric motor 10. The annular stator 14 is mounted in a housing 16 of an annular casing 18 which includes in its thickness an annular cavity 20 in which a coolant of the electric machine in operation. The compressor includes a cover 22 resting on the casing 18 and ensuring rotational guidance of the rotor 12. The cover 22 includes a central orifice 24 for the passage of the rotor shaft 12 and its connection to a compressor wheel as is well known to those skilled in the art.

In operation, the electric motor provides the power necessary for the rotation of the compression wheel, thereby temporarily increasing the compression efficiency. However, this assembly is a source of noise pollution in the motor vehicle. Indeed, the electromagnetic forces applied to the rotor and to the stator in operation lead to micro-displacements of the rotor and the stator relatively to each other at high audible frequencies, typically between 1000 and 20000Hz. These vibrations which are transmitted by the stator to the casing integral with the structural frame of the motor vehicle, induce an increase in the audible background noise in the immediate environment of the vehicle. Unlike other sources of noise, this type of sound source is intrinsic to the operation of the electric motor and this proves difficult to eliminate.

The invention proposes to provide an effective, simple and economical solution to the aforementioned problems.

To this end, it offers a support assembly for an electric machine comprising a casing comprising a housing, of longitudinal axis, inside which is intended to be mounted the stator of the electric machine and a shutter cover d '' an opening of the housing intended to be crossed by the rotor of the electric machine, characterized in that the casing comprises a first annular part intended to radially support internally the stator of the electric machine and a second part supporting the first part, the first annular part being connected to the second part and to the cover by means of elastically deformable means.

According to the invention, the stator of the electric machine is connected to the casing and to the cover by intermediate means which are elastically deformable, thus making it possible to avoid the transmission of high frequency vibrations from the stator to the casing. Consequently, noise pollution is reduced, which improves acoustic comfort inside the passenger compartment of a motor vehicle.

In one possible embodiment, the elastically deformable means comprise annular seals interposed between a first longitudinal end of the first annular part and the second part and between the cover and a second longitudinal end of the first annular part opposite the first end.

According to another characteristic of the invention, one of the first annular part and of the second part may comprise an annular face for centering and supporting the first part on the second part, this annular face being inclined obliquely by relative to the longitudinal axis and an annular seal being applied thereto and held in an annular recess of an L-shaped annular portion of the other of the first annular part and of the second part.

This type of configuration makes it possible to absorb vibrations while carrying out, in a simple manner, the centering of the first part of the casing on the second part of the casing by means of the faces inclined at an oblique angle.

Also, one of the first annular part and of the cover may comprise an annular face for centering and supporting the cover on the first part, this face being inclined obliquely to the longitudinal axis and an annular seal being applied. thereon and held in an annular recess of an L-shaped annular portion of the other of the first annular part and the cover. In this configuration, the cover is centered in a simple manner on the first part of the casing.

According to another characteristic of the invention, the annular centering and bearing face of the first part on the second part is formed on the second part and the annular centering and bearing face of the cover on the first part is formed on the cover, the normal to said annular faces converge towards each other towards the axis of the rotor.

The cover may include another annular face inclined obliquely to the longitudinal axis in abutment on an annular seal arranged in an annular recess of an annular L-shaped portion of the second part for centering and pressing the cover on the second room. In this way, the cover is thus centered and supported on the second end of each of the first part and the second part.

In another practical embodiment of the invention, the first end and the second end of the first part each comprise two coaxial annular grooves formed in a cylindrical face and a radial face, each of said cylindrical and radial faces receiving an annular seal compressed on corresponding cylindrical and radial faces opposite the second part and the cover.

The second part can be annular and surround the first part so as to define therewith an annular space for circulation of a coolant.

The invention also relates to an electric machine, comprising an assembly as described above, a stator being arranged inside the first part and a rotor being engaged inside the stator.

The invention also relates to a compressor electric of supercharging for a motor vehicle, comprising a wheel of compression and an electric drive machine of the wheel of compression in rotation.

The invention will be better understood and other details, characteristics and advantages of the invention will appear on reading the following description given by way of nonlimiting example with reference to the appended drawings in which:

- Figure 1, described above, is a schematic sectional view of an electric machine according to the prior art;

- Figure 2 is a schematic half-sectional view of an electric machine according to a first embodiment of the invention;

- Figure 3A is a schematic view on a larger scale of the rectangular area defined by dotted lines in Figure 2;

- Figure 3B is a view similar to Figure 3A without the annular seal;

- Figure 4A is a schematic view on a larger scale of the oval area delimited in dotted lines in Figure 2;

- Figure 4B is a view similar to Figure 4A without the annular seals;

- Figure 5 is a schematic sectional view of a second embodiment of the invention.

Reference is made simultaneously to Figures 2 and 3 which show a first embodiment of the invention. As a reminder, FIG. 1 relating to the prior art has already been described previously. Items with the same names are referenced by a number plus one hundred.

The electric machine according to the invention is configured to prevent the propagation of frequencies created by the electromagnetic forces applied to the stator and to the rotor, forces which lead to micro-displacements of the rotor and the stator relatively to each other at high frequencies. audible, typically between 1000 and 20000Hz.

As explained above, these vibrations which are transmitted by the stator to the casing integral with the structural frame of the motor vehicle, induce an increase in the audible background noise in the immediate environment of the vehicle.

For this, the invention consists in decoupling the stator 114 from the rest of the electric machine by the use of elastically deformable means.

Thus, no rigid contact exists between the stator 114 and the rest of the electric machine, which makes it possible to correctly stop the noise.

More specifically, in the electric machine according to the invention 100, the casing 118 surrounding the stator 114 of the electric motor is produced in two separate parts, the first part 126 and the second part 128.

According to one embodiment, the first part 126 and the second part 128_ are annular parts. The first part 126 internally defines a housing 116 receiving the stator 114 and the rotor (not shown) in a similar manner to what has been described with reference to FIG. 1. It surrounds the stator 114 and is itself surrounded by the second 128 ring piece. The first 126 and the second 128 parts define between them an annular space 120 for circulation of a coolant.

According to one embodiment of the invention, the housing 116 116 receiving the stator 114 and the rotor, is tubular. According to one embodiment, the first annular part 126 comprises a cylindrical wall 130 having the axis 132 as that of the housing 116. first part 126 comprises a first longitudinal end 134 and a second longitudinal end 136, along the axis 132, the second end 136 being arranged opposite the cover 122. In the description, the term "radially" is used in reference to the axis 132 of the housing 116. An annular flange 138 extending radially inward is formed at the first longitudinal end 136 of the cylindrical wall of the first part 126. This radial annular flange 138 is arranged in with respect to a longitudinal annular radial shoulder 140 of the second part 128 without, however, being in contact with the latter in order to avoid transmission of the vibrati from the first part 126 to the second part 128 as will appear more clearly later.

According to one embodiment, the first end 134 of the first part 126 comprises an annular portion 142 in L formed by an end portion 142a of the cylindrical wall 130 and a radial annular flange 142b extending radially outwards ( figure 4). This annular portion 142 in L of the first end 134 of the first part 126 delimits radially outward an annular recess 142c in L. In the vicinity of its second end 136, the first part 126 comprises, an annular portion 144 in L formed by an end portion 144a of the cylindrical wall 130 and an annular radial rim 144b extending radially outwards. This annular portion 144 in L of the second end 136 of the first part 126 delimits radially outward an annular recess 144c in L.

Note that the L-shaped portions 142, 144 of the first part 126 are symmetrical to one another with respect to a plane perpendicular to the axis 132 of the housing 116.

According to one embodiment, the second annular part 128 comprises a first end 146 and a second end 148, the second end 148 being arranged opposite the cover 122. The first end 146 of the second part 128 extends at the level of the annular shoulder 140 by a cylindrical wall 150. The second part 128 comprises a cylindrical wall 152 having at its first end 146 an annular bulge 154 radially internal having a face 156 annular inclined obliquely so that the normal 156a this face 156 is oriented towards the cover 122 and the longitudinal axis 132. This face 156 is arranged opposite the annular recess 142c in L of the first end 136 of the first part 126. The second end 148 of the second part 128 comprises an L-shaped portion 160 formed by a cylindrical end portion 160a and an annular radial rim 160b s extending radially outward. This annular portion 160 in L of the second end 148 of the second part 128 delimits radially outward an annular recess 160c in L. This portion 160 in L of the second end 148 of the second part 128 is oriented in space in the same way as the L-shaped portion 144 of the second end 136 of the first part 126 and is arranged longitudinally at the same position along the axis 132.

According to one embodiment, the cover 122 comprises two annular ribs radially internal 162 and radially external 164 projecting inside the housing 116 each comprising an annular face 166, 168 inclined obliquely to the axis 132. Normal 166a, 168a with the annular faces 166, 168 of the internal 162 and external 164 ribs are oriented in the direction of the longitudinal axis 132. Each of these normals 166a, 168a converge towards the normal 156 on the annular face 156 of the first end 136 of the cylindrical wall 130 of the second part 126, in the direction of the axis 132 of the housing 116. The normals 166a, 168a of the annular faces 166, 168 of the ribs 162, 164 are substantially parallel to one another.

According to one embodiment, the ribs 162, 164 of the cover 122 are positioned and dimensioned so that the annular face 168 of the external rib 164 comes opposite the annular recess 160c in L of the second end 148 of the second part and in that the directory face 166 of the internal rib 162 comes opposite the annular recess 144c in L of the second end 136 of the first part 126.

According to the invention, elastically deformable means are mounted in the annular recesses 142c, 144c, 160c of the portions 142, 144, 160, in L so as to be interposed between the annular faces 156, 166, 168 of the second part 128 and of the cover 122 and the portions 142, 144, 160 in L of the first part 126 and second part 128. These elastically deformable means are for example annular seals 170, extending over 360 °, which can be made of elastomer. These annular seals 170 have a circular section but other shapes could also be suitable.

The embodiment of Figure 2 using inclined faces 156, 166, 168 on one of the second part 128 and the cover 122 and a portion 142, 144, 160 in L on the other of the first 126 and the second 128 pieces enables a simple centering and pressing of the first piece 126 on the second piece 128 and a centering and pressing of the cover 122 on the first piece 126 and the second piece 128.

In another variant, the L-shaped portion 142 of the first end 134 of the first part 126 could be formed on the first end 146 of the second part 128, the first end 134 of the first part 126 then comprising an inclined face for the support of the annular seal 170. Similarly, the L-shaped portion 144 of the second end 136 of the first part 126 could be formed on the internal rib 162 of the cover 122, the second end 136 of the first part 126 then comprising a face inclined to support the annular seal 170. Also, the L-shaped portion 160 of the second end 148 of the second part 128 could be formed on the external rib 164, the second end 148 of the second part 128 then comprising an inclined face to support the annular seal 170.

In a second embodiment of the invention shown in Figure 5, the cover 122 also includes two annular ribs internal 172 and external 164. The radially external rib 164 of this embodiment is identical to the radially external rib 164 of the previous embodiment. However, the radially internal rib 172 is devoid of an oblique inclined face. The internal rib 172 thus has a substantially rectangular section. The first part 174 comprises a cylindrical wall 152, the first end 134 of which comprises a radial face 176 and a cylindrical face 178 connected to each other and each comprising an annular groove 180. Similarly, the second end 136 of the first part 174 comprises a radial face 182 and a cylindrical face 184 connected to each other and each comprising an annular groove 180.

According to one embodiment, each annular groove 180 houses an annular seal 170 similar to what has those described with reference to the previous embodiment. The annular seals 170 of the annular grooves 180 of the first end 134 of the first part 174 are supported on the radial and cylindrical faces of the second part 186 while the annular seals 170 of the annular grooves 180 of the second end 136 of the first part 174 are supported on one face of the cover 122 and on a radial face of the internal rib 172. The second end 148 of the second part 186 is connected to sealing and damping of vibrations by an annular seal 170 in a similar manner to that which has been described with reference to Fig 2.

In the embodiments shown in the figures, the annular seals 170 are dimensioned so that there is no contact between the first part 126, 174 and the second part 128, 186.

Thus, in the various embodiments of the invention, the interposition of elastically deformable means between the first part 126, 174 and second part 128, 186 allows static decoupling of the first part 126, 174 supporting the stator 114 of the electric motor with the second part 128, 186, which prevents transmission of vibrations intrinsic to the operation of the electric motor to the frame of the motor vehicle and then to the passenger compartment.

Claims (10)

1. Support assembly for an electric machine (100) comprising a casing (118) comprising a housing (116) with a longitudinal axis (132) inside which is intended to be mounted the stator (114) of the machine electric (100) and a cover (122) for closing an opening in the housing (116) intended to be traversed by the rotor of the electric machine (100), characterized in that the casing (1118) comprises a first part (126, 174) annular intended to radially support internally the stator (114) of the electric machine (100) and a second part (128, 186) supporting the first part (126, 174), the first part (126, 174) being connected to the second part (128, 186) and to the cover (122) by means of elastically deformable means. 2. Assembly according to claim 1, characterized in that the elastically deformable means comprise annular seals (170) interposed between a first longitudinal end (134) of the first annular part (126, 174) and of the second part (128, 186) and between the cover (122) and a second longitudinal end (136) of the first annular part (126, 174) opposite the first end (134). 3. The assembly of claim 2, characterized in that one of the first annular part (126 ,, 174) and the second part (128, 186) comprises an annular face (156) for centering and supporting the first part (126, 174) on the second part (128, 186), this annular face (156) being inclined obliquely with respect to the longitudinal axis (132) and an annular seal (170) being applied thereto and held in an annular recess (142c) of an L-shaped annular portion (142) of the other of the first annular part (126, 174) and the second part (128, 186). 4. An assembly according to claim 2 or 3, characterized in that one of the first annular part (126, 174) and of the cover (122) comprises an annular face (166) for centering and supporting the cover (122 ) on the first part (126, 174), this face (166) being inclined obliquely to the longitudinal axis (132) and an annular seal (170) being applied thereon and held in an annular recess ( 144c) of an annular portion (144) in L of the other of the first annular part (126, 174) and of the cover (122). 5. An assembly according to claims 3 and 4, characterized in that the annular face (156) for centering and supporting the first part (126, 174) on the second part (128, 186) is formed on the second part (128, 186) and the annular face (166) for centering and supporting the cover (122) on the first part (126, 174) is formed on the cover (122), the normals (156a, 166a) on said faces annulars (156, 166) converging towards each other towards the longitudinal axis. 6. An assembly according to claim 5, characterized in that the cover (122) comprises another annular face (168) inclined obliquely relative to the longitudinal axis (132) bearing on an annular seal (170) arranged in a annular recess (160c) of an L-shaped annular portion (160) of the second part (128, 186) for centering and pressing the cover (122) on the second part (128, 186). 7. An assembly according to claim 2, characterized in that the first end (134) and the second end (136) of the first part (126, 174) each comprise two coaxial annular grooves (180) formed in a cylindrical face (178 , 182) and a radial face (176, 184), each of said cylindrical (178, 182) and radial (176, 184) faces receiving an annular seal (170) compressed on corresponding cylindrical and radial faces opposite of the second part (128, 186) and of the cover (122). 8. Assembly according to one of claims 1 to 7, characterized in that the second part (128, 186) is annular and surrounds the first part (126, 174) so as to define therewith an annular space (120 ) circulation of a coolant. 9. Electric machine, characterized in that it comprises an assembly according to one of the preceding claims, a stator (114) being arranged inside the first part (126, 174) and a rotor being engaged in inside the stator (114). 5 10. Electric supercharger for a motor vehicle, comprising a compression wheel and an electric machine (100) according to claim 9 for driving the compression compression wheel. 2/3